Controller for electric motors.



A. J. HORTON CONTROLLER FOB. ELECTRIC MOTORS.

APPLICATION FILED JULY 6, 1908.

991,206. L I Patentd May 2, 1911.

' tion.

a slow speed time, and then automatically brought up to anypredetermined maximum speed by the UNITED srn'rns PATENT" orricn.

ALBERT J. HOB-TON, F WHTTE PLAINS, NEW YCRK, ASSIGNOB T0,.1HE CUTLER-HAMMER MFG. 00., OLE MILWAUKEE, WISCONSIN, A CQRPORATION OF WIS- CONSIN.

CONTROLLER FOR ELECTRIC MOTORS.

Specification of Letters Patent.

Patented May 2, 1911.

Application filed July 6, 1908. Serial No. 442,174.

To all whomii may concern:

Be it known that I, ALBERT J. Ho'nron, a citizen of the United States,residing at White Plains, in the county ofWestchester and State of NewYork, have invented new and useful Improvements in Controllers forElectric Motors, of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawing,forming a part of this specifica- My invention relates to controllersfor electric motors, and more, particularly to those for causing themotor to operate at different speeds.

One' object of my invention is to provide means whereby the motor may beoperated for any desired period of manipulation of a single switch.

Other objects of my invention will be hereinafter set forth. 4

In the accompanying drawing I have diagrammatically illustrated one formof con-' troller embodying my invention.

The controller shown in the drawing comprises an electromagneticallyoperated main switch, an electromagnctically operated speed controllerand a pilot switch for controlling the operationof said main switch andsaid controller. As will hereinafter he explained, the pilot switch alsocontrols the direction of the flow of current through the motor.

The main switch 1 is carried by the plum ger 2 of a solenoid 3. Thisswitch is provided with main contact brushes 4 and 5 and arcing contacts6 and 7, which are carried on spring arms. The brushes 4 and 5 areadapted to engage stationary contacts 8 and contacts 10 and 1.1 areconnected to the contacts 8 and 9.

The speed controller, which I have shown, is of the same construction asthat shown in my former application, Serial No. 430,829, filed May 4,1908.

speed controller comprises an arm 14 piv oted at 15. At its outer end,the arm 14 car- As thearm 14 is ries brushes l6 and 17.

' to one Generally described, the

moved the brush 16 is adapted to sweep over a contact segment 18 and aseries of contacts 19, while the brush 17 is adapted to sweep over aseries of contacts 21 and a segment 22. The contacts 19 are connected toa field regulating resistance 20, which is also connected end of thesegment 18. All but the first of the series of contacts 21 are connectedto an armature resistance 23, which is also connected to one end of thesegment 22. The arm 14 is connected by an insulating link 24 to theplunger 25 of a solenoid 26. The solenoid 26 is provided with anadjustable core or plug 27 which is supported by a pivoted lever 28. Thelever 28 is provided at. its free end with a handle 29 and a pin 30. Thepin 30 is adapted to fit into any of the apertures 31 in a rack 32. Thisarrangement provides means whereby the lever 28 may be moved to, andmaintained, in any desired position to adjust the position of the plug27 within the winding 26. The lever 28 is provided with a lug 33 towhich is pivoted a switch 34. The free end of the switch '34 is adaptedto engagea stationary contact 35. A pin 37, extending through the plug27 and projecting below the end there of, provides means whereby theswitch 34 will be opened by the plunger 25 when the same reaches thelimit of its upward movement. By usting the position of the plug 27within the winding 26, the range of movement of the plunger 25 may belimited to any desired extent, which results in the limitation of therange of movement of the controlling arm 14. Hence, the controller maybe set to cause any predetermined amount of armature resistance 23 andto insert any predetermined amount of field regulating resistance 20.The movement of the arm 14-is retarded by a dash-pot 38 which has itspiston 39 connected to said arm. When the arm 14 is in its lowermostposition. the brush 17. carried thereby, bridges the first trio of thecontacts 21, while the brush 16 engages segment 18. i

.The pilot switch comprises a movable arm 40 pivoted at 41 and providedwith an operating handle 42. The member 40 is of irregular shape andcarries contact brushes 43, 44 and 45 which are arranged thereon in astaggered manner and radiallydisposed to the axis thereof. 'Thebrusliescarried by the i arm 40 are elongated and are each adapted thearm 14 tocut out to move over and engage with two sets of contactsegments, which will now be described: The upper end of the brush 43 isadapted to engage either of the contact segments 46 or 47, while thelower end of said brush engages a contact segment 50. When the'arm 40 ismoved to its extreme left-hand position, the brush 43 engages a contact48, and when said arm is in its extreme righthand position, the brush 43engages a con- .tact 49. At its upper end the brush 44 enga es thecontact segment 50, while its lower ,en is adapted toengage either ofthe contacts 51 or 52. The upper end of-the brush 45 is adapted toengage either of the contact segments 52 or 53, While its lower endengages a contact segment 54. 'As shown in the drawing, the contactsegments are so arranged that when the arm 40 is in a Vertical positionthe brush 43 lies between contact segments 46 and 47, and engagescontact segment 50. The brush 44 also engages contact segment 50 andlies between contact segments 51 and 52, while the brush 45 engagescontact segment 54 and lies between contact segments 52 and 53. Thesegments 46 and 47 are electrically connected and segments 51 and 53 arealso electrically connected.

I shall now describe the circuit arrangement of the controller: Currentis supplied from main lines 55 and 56.

- 56 is connected by conductor 57 to the con ment 54 of the pilotswitch.

trolling arm 14. The contact segment 22 is connected by conductor 58 tocontact seg- Contact seg ment 18 is connected by conductor 59 to oneterminal of the shunt field winding f of the switch is motor, the otherterminal of said winding being connected by conductor 60 to the mainline 55. Contact segment 53 of the pilot connected by conductor 61 tocontact 8. Contact segment 52 is connected by conductors 62 and 63 toone terminal of the motor armature a, the other terminal of the armaturebeing connected by conductor 64 to contact 9. Contact 13 is connected toconductor 64. Contact 12 is connected by conductor 65, through aresistance 66, to conductor 63. Contact segment 50 is connected by;conductor 67 to main line 55. Main line 56- is connected :by conductor68 to one ter-' to acne terminal of the winding 3,; :while the otherterminal of the windingfiis connected by conductor 74 to-the first. ofthe. series of contacts 21,. which is cqnnectedithrough a resistance 75byaconducton 7 6;to;ma in line 56.

The main line" Circuit will thengbe I. shall now describe the operationof the controller: Assuming that the arm 40 of the ilot switch is in theposition shown in the rawing, the main switch will be open and the arm14 in its lowermost position. It now the arm 40 be moved to the right soas to bring the brush 43 into contact with the segment 47, the brush 44into contact with segment 52, and the brush 45 into contact with thecontact segment 53, circuit will be closed through the operating winding3 of the main line switch. This circuit may be traced from main line 56by conductor 57 through the arm 14 to tacts 21 by conductor 74, throughthe winding 3 by conductor 73 to contact segment 47, across brush 43 tosegment 50, and thence by conductor 67 to the main line 55. This willenergize the winding 3 and cause the same to close the main switch 1,thereby raising the contacts 6 and 7 from the contacts 12 and 13. Assoon as the main switch is closed circuit will be closed through themotor armature a. The armature circuit "may be traced from main line 56,by conductor 57 through the arm 14, brush 17, to the second of theseries of contacts 21, through all of the resistance conductor 58 tocontact segment 54, across brush 45 to contact segment 53, by conductor61 to contact 8, across main switch 1 to contact 9, thence by, conductor64 through. the armature a, by conductors 63 and 62 to contactlsegment52, across brush 44 to contact segment '50, and then by way of conductor67 to the main line 55. I

The shunt field winding f being connected across the supply circuit, thesame will be energized before the armature circuit is closed. Thecircuit for the shunt field Winding f extends from main line 56 byconductor 57, through the arm 14, brush 16 to contact segment 18, thenceby conductor 59 through the shunt field winding f, and by conductor 60to the main line -55. In this position of the pilot switch it will beseen that all of the armature resistance 23 is included in circuit withthe armature a, and, therefore,

the motor will be operated at a slow speed. The pilot switch may be leftin this position as long as desired. The mot'or circuit may be opened atany time by merely moving the arm 40 back to a central position, whichopens the circuit of thebperating Winding of the mainswitch. The mainswitch will then fall and open the motor circuit. When it is desired toincrease the motor speed, the arm 40 of the pilot switch is moved to itsextreme right-hand position, in which positionthe brushc43 willen agecontact 49.

closed t ating; magnet 26 of the speed controller. This circuit extendsfrom the main line- 56 by, conductor 68, through conductor. 69, throughthe arm winding 28, lug v33,

the first of the conirough the oper switch 34, contact 35 by conductor71 to contact 48, by conductor 7 2 to contact 49, by

brush 43 to contact segment 50, and thence by conductor 67 to main line55. The magnet. 26 will then respond and raise its plunger 25, thusraising the arm 14.

As shown in the drawing, the stationary plug is adjusted to permit theplunger 25 to raise the arm'14 until the brush 17 engages the contactsegment 22, and the brush 16 engages the first of the contacts 19. Itwill merely inserting a portion of the field resistance, it should beunderstood that the device ma be set so as to insert all of the fieldresistance, or to remove only'a part of the armature resistance, asdesired, according tothe speed at which it is desired to operate themotor. It will thus be seen that in the final position of the ilotswitch the motor will be gradually brought up to the maximum speed andwill continue to operate at a maximum speed until the main switch 1 isopened, or, until the brush 43 is moved oil? of the contact 49,whereupon, the winding 26 would be de'elnergized. and the arm 14 wouldfall; first removing the field resistance from circuit and theninserting the armature resistance in circuit. The motor would thencontinue to operate at a slow speed until the arm 40 of the pilot switchwas moved to the position shown in the drawing.

, Upon the opening of the main switch 1, the contacts 6 and 7 carriedthereby, will engage the contacts 12 and 13 and establish a dynamicbraking circuit across the terminals of the armature a. This circuit maybe traced from one terminal of the armature a. by conductor 64 tocontact 13, to contact 7, across the spring arms of the main. switch tocontact 6, to contact 12, thence'by conductor 65 through the resistance66 and by conductor 63 to the opposite terminal of the armature. Theestablishment of the braking circuit just described, will quickly bringthe Emotor to a state of rest.

\ As soon as the arm ,14 leaves the first of the series of contacts21upon its upward movement, the short-circuit around the resistance 75,through said arm, is opened and said resistance insertedin circuit withthe winding The circuit of the winding 3 will then extend from conductor57 byconductor 76, through the resistance 75 to the first of thecontacts 2, and thence through the winding 3, as already traced. The in-"SQI'tlOII of the resistance 75 cuts downthe fiow of current through thewinding 3 to an amount just suflicient to maintain the main SWltCllclosed, and prevents the winding from closing the main switch after thesame has been opened It will thus be seen that after the main switch 1is opened, either by the failure of voltage, or by the operation of thepilot switch, said main switch cannot again be closed until the arm14reaches' its lowermost position, whereupon it will shortcircuit theresistance 75- and permit the winding 3 to respond. The motor is thusprotected against damage in case an attempt is made to again start thesame before the armature resistai ce is inserted in circuit.

If it is desired to operate the motor in the opposite direction fromthat previously described, the arm 40 of the pilot switch is moved tothe left so as to move the brush 43 into engagement with the contactsegment 46; the brush ,44 in cont-act with the segment 51, and the brush45 in contact with segment 52. In this position of the pilot switch,circuit will first be closed through the winding 3 and the main switch 1will be closed thereby, thus closing the armature circuit. The armaturecircuit may now'be traced from conductor 56, through the arm 14, throughthe resistance 23, contact ment 22, conductor 58 to segment 54, acrossbrush 45 to segment 52, thence by conductors 62 and 63, through themotor armature a, by

. conductor 64 to contact 9, across switch 1 to contact 8, by conductor61 to segment 53 of the pilot switch, across to segment 51, by brush 44to segment 50, and thence by conductor 67 to main line 55. It will thusbe seen that current flows through the motor armature in an oppositedirection to that previously described, and, therefore, the m0- tor willrun in. an opposite direction. The field circuitmay be traced as alreadydescribed. When it is desired to cause the m0- tor to operate at itsmaximum speed, the arm 40 is moved to its extreme left-hand position,whereupon the brush 43 willengage contact 48 and close the circuit ofthe winding 26. The winding 26 will then respond and draw the arm 14upwardly to: gradually remove the armature resistance from circuit andthen insert the field resistance.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a controller for electric motors, in combination, an automaticallyoperated main switch, a pilot switch adapted, when in a predeterminedposition, to cause said main switch to respond fdr obtaining a slowspeed of the motor, and an automatically operated accelerating devicearranged. to respond when thejpilot switch is moved to another positiontoincrease the speed of the motor, said pilot switch having contacts.included in the motor circuit for controlling the direction of flow ofcurrent therein.

2. In a controller for electric motors,

an electroresponsive mam combination,

switch, an electroresponsive accelerating device, and a pilot switchdirectly controlling the energizing circuits of said main switch andsaid accelerating device and movable into a position for causingresponse of the main switch alone for slow speed and into anotherposition for also causmg the accelerating device to respond to increasethe motorspeed, said pilot switch inherently controlling the directionof operation of the motor.

3. In a controlling device for electric motors,- in combination, anautomatically operated main switch, an automatically operated speedcontrolling device, means for adjusting said device to cause the motorto operate at different predetermined speeds, and a pilot switchadapted, when in one position, to cause said main switch to be closedand when in another position to cause the operation of said speedcontrolling device.

4. In a controlling device for electric motors, in combination, a mainswitch, an electromagnetic winding for operating the same, a speedcontrolling device, an electromagnetic winding for operating the same,means for adjusting said controller to cause the motor to operate atdilferent predetermined speeds, and a pilot switch adapted, when in oneposition, to close the circuit of the operating winding of said mainswitch and when in another position to close the circuit of theoperating winding of said speed controlling device.

5. In a controller for electric motors, in combination, a pilot switchhaving contacts for reversing the motor, an automatically operated mainswitch controlled directly by said pilot switch and adapted, whenclosed, to cause the motor to operate at a slow speed, an automaticallyoperated accelerating device for the motor controlled by said pilotswitch, said pilot switch being movable to cause the operation of boththe main switch and accelerating device or the, main switch alone andmeans whereby the maximum speed oi the motor may be varied atWill-independently of said pilot switch."

6. In a controller for electric motors, in combination, 'a pilot switchmovable in opposite directions for inherently varying the circuitconnections of the motor to cause the same to operate in eitherdirection, an electroresponsive main switch, and an electroresponsiveaccelerating device for the motor,

said main switch and accelerating device being controlled directly bysaid pilot switch,

and said pilot switch being adapted, when moved ineither direction, tocause both said tbh" and said accelerating device to respond to bringthe motor up to a predetermined high speed or to cause the main switchalone to respond for obtaining a slow speed of the motor.

7. In a controller for electric motors, in combination, an automaticallyoperated main switch, an automatically operated speed controllingdevice, means for adjusting said device to cause the motor to operateatdifferent predetermined speeds, and a pilot switch adapted to cause themotor to operate in either direction, said pilot switch, when in certainpositions, being adapted to cause said lnain switch to be closed andwhen in other positions to cause said speed controlling device to beactuated.

8. In a controlling device for electric motors, in combination, a mainswitch, an operating winding therefor, a speed controlling device, anoperating winding therefor, means for adjusting said speed controllingdevice to cause the motor to operate at any predetermined speed,-and apilot switch for causing the motor to operate in either direction, saidswitch, when moved in either direction, being adapted to first close thecircuit of the operating winding of said main switch and then to closethe circuit of the operating winding of said speed controlling device.

9. In a controller for electric motors, in combination, an automaticallyoperated main switch, an adjustable automatically operated speedcontrolling device, a 'pilot switch adapted, when in one position, tocause said main switch to be closed and when in another position tocause said speed controlling device to be actuated, and a dynamicbraking circuit across, the terminals of the motor armature adapted tobe completed when said main switch is open.

10. In a controller for electric motors, in combination, anautomatically operated main switch, an adjustable automatically operatedspeed controlling device, a pilot switch movable' in opposite directionsto reverse the operation of the motor, said pilot switch, when moved ineither direction, being adapted to first cause the operation of saidsaid speed controlling device, and a dynamic braking circuit across theterminals of the motor armature adapted to be closed by said main switchwhen open.

In witness whereof, I have hereunto subscribed my name in the presenceof two Witnesses'.

ALBERT J. HORTON. Witnesses:

WILLIAM L. CULLY, CHARLES B. BAKER.

main switch and then cause the operation of

